In Information Technology (IT) systems it is common to monitor the performance of the software and hardware that make up an IT system. Such monitoring enables the administrators and customers of such a system to ensure that the system performs within agreed limits. Such limits are often specified in one or more Service Level Agreements (SLAs).
There are many performance measures applied to IT systems. Some performance measures measure the performance of the runtime platform or environment of an application program while other performance measures are aimed at the performance of the application programs themselves. Some performance measures for runtime platforms use the rate of throughput for an individual platform resource, such as a message queue, or the completion time of a particular class of processing request, to provide measures of the performance of the platform. These platform performance measures provide an indication of the performance of the platform itself. Some performance measures for application programs assign units to application program processes, these units are then used to calculate the load that the application will put on a platform on which the application program is deployed. Such units may also be used to estimate the platform processing capacity required for the application program. In other words, these performance measures provide an indication of the impact of the application program in the runtime platform. However, using any of these systems it is difficult to determine the effect of the performance of the runtime platform itself on the performance of an application program running on that platform.